Split onc::IsRecommendedValue into onc_utils.cc

chromeos/network/onc/onc_utils.h

Index: chromeos/network/onc/onc_utils.h
diff --git a/chromeos/network/onc/onc_utils.h b/chromeos/network/onc/onc_utils.h
index 261ae49dbabbcf802a903f1f80cd2c037599f508..c31cd2e4b4b75e5236942c58e5c58e91390c9eb0 100644
--- a/chromeos/network/onc/onc_utils.h
+++ b/chromeos/network/onc/onc_utils.h
@@ -130,6 +130,10 @@ CHROMEOS_EXPORT bool ResolveServerCertRefsInNetwork(
 CHROMEOS_EXPORT NetworkTypePattern NetworkTypePatternFromOncType(
     const std::string& type);
 
+// Returns true if |property_key| is a recommended value in the ONC dictionary.
+CHROMEOS_EXPORT bool IsRecommendedValue(const base::DictionaryValue* onc,
+                                        const std::string& property_key);
+
 }  // namespace onc
 }  // namespace chromeos